We are currently working on solving the structure of the hammerhead ribozyme at high resolution with various modified inhibitors bound. We have three closely related crystal forms that diffract beyond 2.0 E. although two of the crystal forms are anisotropically disordered, one that grows in the presence of lutetium (a lanthanide) is well-ordered. We have collected both a single-wavelength dataset (on beamline 7-1) and a four-wavelength dataset (on beamline 1-5) for multiwavelength anomalous dispersion phasing. The lutetium ions bind in special positions, allowing us to phase half the reflections with high figure-of-merit, while the other half are not phased. We are searching for a second derivative in order to solve the structure.